报告人：Francis Duplessis (Arizona State University)

时间：2015年9月1日下午4：00

地点：东区理化大楼18层天文台报告厅

报告摘要：In this talk I will discuss a few interesting features of a gravitational action that differs significantly from GR, namely we will look at a Lagrangian made up solely from the square of the Ricci scalar. For instance, the Birkhoff theorem fails and allows for a rich class of static spherical solutions in vacuum. The study of this action can be motivated by noting its similarities with actions that can be obtain from the strong coupling limit of GR.